The Collaborative International Dictionary of English v.0.48:

Pleasance \Pleas"ance\, n. [F. plaisance. See Please.]
   1. Pleasure; merriment; gayety; delight; kindness. [Archaic]
      --Shak. "Full great pleasance." --Chaucer. "A realm of
      pleasance." --Tennyson.
      [1913 Webster]

   2. A secluded part of a garden. [Archaic]
      [1913 Webster]

            The pleasances of old Elizabethan houses. --Ruskin.
      [1913 Webster]

WordNet (r) 3.0 (2006):

pleasance
    n 1: a pleasant and secluded part of a garden; usually attached
         to a mansion
    2: a fundamental feeling that is hard to define but that people
       desire to experience; "he was tingling with pleasure" [syn:
       pleasure, pleasance] [ant: pain, painfulness]

Moby Thesaurus II by Grady Ward, 1.0:

41 Moby Thesaurus words for "pleasance":
   affability, agreeability, agreeableness, amenity, amiability,
   amicability, bliss, blissfulness, common, commons, compatibility,
   complaisance, congeniality, cordiality, enjoyableness,
   felicitousness, geniality, goodliness, goodness, graciousness,
   gratefulness, harmoniousness, mellifluousness, mellowness,
   niceness, paradise, park, pleasantness, pleasantry, pleasingness,
   pleasurability, pleasurableness, pleasure, pleasure garden,
   pleasure ground, pleasurefulness, public park, rapport, sweetness,
   sweetness and light, welcomeness